:root {
  --void: #05070c;
  --ink: #e8eef6;
  --dim: rgba(232, 238, 246, 0.45);
  --faint: rgba(232, 238, 246, 0.18);
  --cyan: #7ec8ff;
  --serif: "Noto Serif SC", "Songti SC", "STSong", Georgia, serif;
  --sans: "Noto Sans SC", "PingFang SC", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--void);
  color: var(--ink);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
  cursor: default;
  user-select: none;
}

#stage {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

#hud {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 5;
}

#brand {
  position: absolute;
  top: 28px;
  left: 32px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  opacity: 0;
  transition: opacity 1.2s ease;
}

#brand.visible {
  opacity: 1;
}

.brand-kicker {
  font-size: 10px;
  letter-spacing: 0.28em;
  color: var(--dim);
  font-weight: 500;
}

.brand-title {
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--ink);
}

#chapter-block {
  position: absolute;
  left: 50%;
  bottom: 12vh;
  transform: translateX(-50%);
  width: min(720px, 86vw);
  text-align: center;
  opacity: 0;
  transition: opacity 0.9s ease;
}

#chapter-block.visible {
  opacity: 1;
}

#chapter-kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  margin-bottom: 12px;
  opacity: 0.85;
}

#chapter-title {
  font-family: var(--serif);
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 500;
  letter-spacing: 0.12em;
  line-height: 1.25;
  text-shadow: 0 2px 24px rgba(0, 0, 0, 0.55);
}

#chapter-desc {
  margin-top: 14px;
  font-size: clamp(13px, 1.2vw, 15px);
  line-height: 1.75;
  color: var(--dim);
  letter-spacing: 0.04em;
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.6);
}

#status-bar {
  position: absolute;
  top: 30px;
  right: 32px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--dim);
  opacity: 0;
  transition: opacity 1s ease;
}

#status-bar.visible {
  opacity: 1;
}

#play-state.paused {
  color: #ffb04a;
}

#hint {
  opacity: 0.55;
  font-size: 10px;
}

#progress {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 28px;
  z-index: 6;
  pointer-events: none;
  opacity: 0;
  transition: opacity 1s ease;
}

#progress.visible {
  opacity: 1;
}

#progress-fill {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 2px;
  width: 0%;
  background: linear-gradient(90deg, rgba(126, 200, 255, 0.15), var(--cyan));
  box-shadow: 0 0 12px rgba(126, 200, 255, 0.55);
}

#progress-marks {
  position: absolute;
  inset: 0;
  pointer-events: auto;
}

.mark {
  position: absolute;
  bottom: 0;
  width: 14px;
  height: 22px;
  transform: translateX(-50%);
  cursor: pointer;
}

.mark::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 1px;
  height: 10px;
  background: rgba(232, 238, 246, 0.28);
  transform: translateX(-50%);
  transition: background 0.2s ease, height 0.2s ease;
}

.mark:hover::after,
.mark.active::after {
  background: var(--cyan);
  height: 16px;
}

#intro {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: grid;
  place-items: center;
  background: radial-gradient(ellipse at center, rgba(5, 7, 12, 0.2) 0%, rgba(5, 7, 12, 0.92) 70%, #05070c 100%);
  transition: opacity 1.6s ease, visibility 1.6s;
  cursor: pointer;
}

#intro.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.intro-inner {
  text-align: center;
  padding: 0 24px;
  animation: introIn 1.8s ease both;
}

.intro-kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.32em;
  color: var(--cyan);
  margin-bottom: 22px;
  opacity: 0.8;
}

.intro-title {
  font-family: var(--serif);
  font-size: clamp(42px, 7vw, 72px);
  font-weight: 500;
  letter-spacing: 0.28em;
  margin-left: 0.28em;
  line-height: 1.1;
}

.intro-sub {
  margin-top: 22px;
  font-size: 14px;
  line-height: 1.9;
  color: var(--dim);
  letter-spacing: 0.06em;
}

.intro-line {
  width: 64px;
  height: 1px;
  margin: 28px auto 18px;
  background: linear-gradient(90deg, transparent, rgba(126, 200, 255, 0.7), transparent);
}

.intro-meta {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--faint);
  color: rgba(232, 238, 246, 0.35);
}

.intro-error {
  margin-top: 20px;
  font-size: 13px;
  line-height: 1.7;
  color: #e8a090;
  max-width: 420px;
  margin-left: auto;
  margin-right: auto;
}

#fade-veil {
  position: fixed;
  inset: 0;
  background: #000;
  opacity: 1;
  pointer-events: none;
  z-index: 8;
  transition: opacity 2s ease;
}

#fade-veil.clear {
  opacity: 0;
}

@keyframes introIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 720px) {
  #brand {
    top: 18px;
    left: 18px;
  }

  #status-bar {
    top: 18px;
    right: 18px;
  }

  #hint {
    display: none;
  }

  #chapter-block {
    bottom: 10vh;
  }
}